diff --git a/test/functional/abc-cmdline.py b/test/functional/abc-cmdline.py
--- a/test/functional/abc-cmdline.py
+++ b/test/functional/abc-cmdline.py
@@ -36,7 +36,7 @@
         netinfo = self.nodes[0].getnetworkinfo()
         subversion = netinfo['subversion']
         pattern = re.compile(pattern_str)
-        assert(pattern.match(subversion))
+        assert pattern.match(subversion)
 
     def excessiveblocksize_test(self):
         self.log.info("Testing -excessiveblocksize")
diff --git a/test/functional/abc-finalize-block.py b/test/functional/abc-finalize-block.py
--- a/test/functional/abc-finalize-block.py
+++ b/test/functional/abc-finalize-block.py
@@ -75,7 +75,7 @@
             def check_block():
                 for tip in node.getchaintips():
                     if tip["hash"] == block:
-                        assert(tip["status"] != "active")
+                        assert tip["status"] != "active"
                         return tip["status"] == status
                 return False
             wait_until(check_block)
diff --git a/test/functional/abc-high_priority_transaction.py b/test/functional/abc-high_priority_transaction.py
--- a/test/functional/abc-high_priority_transaction.py
+++ b/test/functional/abc-high_priority_transaction.py
@@ -59,8 +59,8 @@
         mempool = self.nodes[0].getrawmempool(True)
         # assert that all the txns are in the mempool and that all of them are hi prio
         for i in txids:
-            assert(i in mempool)
-            assert(mempool[i]['currentpriority'] > hiprio_threshold)
+            assert i in mempool
+            assert mempool[i]['currentpriority'] > hiprio_threshold
 
         # mine one block
         self.nodes[0].generate(1)
@@ -80,14 +80,14 @@
         mempool = self.nodes[0].getrawmempool(True)
         # assert that all the txns are in the mempool and that all of them are hiprio
         for i in txids:
-            assert(i in mempool)
-            assert(mempool[i]['currentpriority'] > hiprio_threshold)
+            assert i in mempool
+            assert mempool[i]['currentpriority'] > hiprio_threshold
 
         # mine one block
         self.nodes[0].generate(1)
 
         self.log.info("Assert that all high prio transactions have been mined")
-        assert(self.nodes[0].getmempoolinfo()['bytes'] == 0)
+        assert self.nodes[0].getmempoolinfo()['bytes'] == 0
 
 
 if __name__ == '__main__':
diff --git a/test/functional/abc-magnetic-anomaly-mining.py b/test/functional/abc-magnetic-anomaly-mining.py
--- a/test/functional/abc-magnetic-anomaly-mining.py
+++ b/test/functional/abc-magnetic-anomaly-mining.py
@@ -108,10 +108,10 @@
             txid_decoded = int(txid, 16)
 
             # Assert we got the expected metadata
-            assert(expectedFeeSats == txn['fee'])
-            assert(expectedSigOps == txn['sigops'])
+            assert expectedFeeSats == txn['fee']
+            assert expectedSigOps == txn['sigops']
             # Assert transaction ids are in order
-            assert(last_txid == 0 or last_txid < txid_decoded)
+            assert last_txid == 0 or last_txid < txid_decoded
             last_txid = txid_decoded
 
 
diff --git a/test/functional/abc-mempool-coherence-on-activations.py b/test/functional/abc-mempool-coherence-on-activations.py
--- a/test/functional/abc-mempool-coherence-on-activations.py
+++ b/test/functional/abc-mempool-coherence-on-activations.py
@@ -193,7 +193,7 @@
         # send a txn to the mempool and check it was accepted
         def send_transaction_to_mempool(tx):
             tx_id = node.sendrawtransaction(ToHex(tx))
-            assert(tx_id in node.getrawmempool())
+            assert tx_id in node.getrawmempool()
 
         # checks the mempool has exactly the same txns as in the provided list
         def check_mempool_equal(txns):
diff --git a/test/functional/abc-p2p-compactblocks.py b/test/functional/abc-p2p-compactblocks.py
--- a/test/functional/abc-p2p-compactblocks.py
+++ b/test/functional/abc-p2p-compactblocks.py
@@ -313,7 +313,7 @@
         # Was it our block ?
         cmpctblk_header = test_p2p.last_cmpctblock.header_and_shortids.header
         cmpctblk_header.calc_sha256()
-        assert(cmpctblk_header.sha256 == b1.sha256)
+        assert cmpctblk_header.sha256 == b1.sha256
 
         # Send a large block with numerous transactions.
         test_p2p.clear_block_data()
@@ -327,7 +327,7 @@
         # Was it our block ?
         cmpctblk_header = test_p2p.last_cmpctblock.header_and_shortids.header
         cmpctblk_header.calc_sha256()
-        assert(cmpctblk_header.sha256 == b2.sha256)
+        assert cmpctblk_header.sha256 == b2.sha256
 
         # In order to avoid having to resend a ton of transactions, we invalidate
         # b2, which will send all its transactions in the mempool.
@@ -348,7 +348,7 @@
         test_p2p.send_and_ping(msg_cmpctblock(comp_block.to_p2p()))
 
         # Check that compact block is received properly
-        assert(int(node.getbestblockhash(), 16) == b2.sha256)
+        assert int(node.getbestblockhash(), 16) == b2.sha256
 
 
 if __name__ == '__main__':
diff --git a/test/functional/abc-parkedchain.py b/test/functional/abc-parkedchain.py
--- a/test/functional/abc-parkedchain.py
+++ b/test/functional/abc-parkedchain.py
@@ -46,9 +46,9 @@
         wait_for_tip(parking_node, parked_tip)
 
         # Let's park the chain.
-        assert(parked_tip != tip)
-        assert(block_to_park != tip)
-        assert(block_to_park != parked_tip)
+        assert parked_tip != tip
+        assert block_to_park != tip
+        assert block_to_park != parked_tip
         node.parkblock(block_to_park)
         assert_equal(node.getbestblockhash(), tip)
 
@@ -156,7 +156,7 @@
             def check_block():
                 for tip in parking_node.getchaintips():
                     if tip["hash"] == block:
-                        assert(tip["status"] != "active")
+                        assert tip["status"] != "active"
                         return tip["status"] == "parked"
                 return False
             wait_until(check_block)
diff --git a/test/functional/abc-replay-protection.py b/test/functional/abc-replay-protection.py
--- a/test/functional/abc-replay-protection.py
+++ b/test/functional/abc-replay-protection.py
@@ -174,7 +174,7 @@
 
         def send_transaction_to_mempool(tx):
             tx_id = node.sendrawtransaction(ToHex(tx))
-            assert(tx_id in set(node.getrawmempool()))
+            assert tx_id in set(node.getrawmempool())
             return tx_id
 
         # Before the fork, no replay protection required to get in the mempool.
@@ -246,7 +246,7 @@
 
         # Non replay protected transactions are not valid anymore,
         # so they should be removed from the mempool.
-        assert(tx_id not in set(node.getrawmempool()))
+        assert tx_id not in set(node.getrawmempool())
 
         # Good old transactions are now invalid.
         send_transaction_to_mempool(txns[0])
@@ -279,11 +279,11 @@
             elif txid == replay_tx1_id:
                 found_id1 = True
 
-        assert(found_id0 and found_id1)
+        assert found_id0 and found_id1
 
         # And the mempool is still in good shape.
-        assert(replay_tx0_id in set(node.getrawmempool()))
-        assert(replay_tx1_id in set(node.getrawmempool()))
+        assert replay_tx0_id in set(node.getrawmempool())
+        assert replay_tx1_id in set(node.getrawmempool())
 
         # They also can also be mined
         block(5)
@@ -293,23 +293,23 @@
         # Ok, now we check if a reorg work properly across the activation.
         postforkblockid = node.getbestblockhash()
         node.invalidateblock(postforkblockid)
-        assert(replay_tx0_id in set(node.getrawmempool()))
-        assert(replay_tx1_id in set(node.getrawmempool()))
+        assert replay_tx0_id in set(node.getrawmempool())
+        assert replay_tx1_id in set(node.getrawmempool())
 
         # Deactivating replay protection.
         forkblockid = node.getbestblockhash()
         node.invalidateblock(forkblockid)
         # The funding tx is not evicted from the mempool, since it's valid in
         # both sides of the fork
-        assert(replay_tx0_id in set(node.getrawmempool()))
-        assert(replay_tx1_id not in set(node.getrawmempool()))
+        assert replay_tx0_id in set(node.getrawmempool())
+        assert replay_tx1_id not in set(node.getrawmempool())
 
         # Check that we also do it properly on deeper reorg.
         node.reconsiderblock(forkblockid)
         node.reconsiderblock(postforkblockid)
         node.invalidateblock(forkblockid)
-        assert(replay_tx0_id in set(node.getrawmempool()))
-        assert(replay_tx1_id not in set(node.getrawmempool()))
+        assert replay_tx0_id in set(node.getrawmempool())
+        assert replay_tx1_id not in set(node.getrawmempool())
 
 
 if __name__ == '__main__':
diff --git a/test/functional/abc-rpc.py b/test/functional/abc-rpc.py
--- a/test/functional/abc-rpc.py
+++ b/test/functional/abc-rpc.py
@@ -30,7 +30,7 @@
         netinfo = self.nodes[0].getnetworkinfo()
         subversion = netinfo['subversion']
         pattern = re.compile(pattern_str)
-        assert(pattern.match(subversion))
+        assert pattern.match(subversion)
 
     def test_excessiveblock(self):
         # Check that we start with DEFAULT_MAX_BLOCK_SIZE
diff --git a/test/functional/feature_bip68_sequence.py b/test/functional/feature_bip68_sequence.py
--- a/test/functional/feature_bip68_sequence.py
+++ b/test/functional/feature_bip68_sequence.py
@@ -88,7 +88,7 @@
         self.nodes[0].sendtoaddress(new_addr, 2)
 
         utxos = self.nodes[0].listunspent(0, 0)
-        assert(len(utxos) > 0)
+        assert len(utxos) > 0
 
         utxo = utxos[0]
 
@@ -315,7 +315,7 @@
             self.nodes[0].generate(1)
             cur_time += 600
 
-        assert(tx2.hash in self.nodes[0].getrawmempool())
+        assert tx2.hash in self.nodes[0].getrawmempool()
 
         test_nonzero_locks(
             tx2, self.nodes[0], use_height_lock=True)
@@ -329,26 +329,26 @@
         # Advance the time on the node so that we can test timelocks
         self.nodes[0].setmocktime(cur_time + 600)
         self.nodes[0].generate(1)
-        assert(tx2.hash not in self.nodes[0].getrawmempool())
+        assert tx2.hash not in self.nodes[0].getrawmempool()
 
         # Now that tx2 is not in the mempool, a sequence locked spend should
         # succeed
         tx3 = test_nonzero_locks(
             tx2, self.nodes[0], use_height_lock=False)
-        assert(tx3.hash in self.nodes[0].getrawmempool())
+        assert tx3.hash in self.nodes[0].getrawmempool()
 
         self.nodes[0].generate(1)
-        assert(tx3.hash not in self.nodes[0].getrawmempool())
+        assert tx3.hash not in self.nodes[0].getrawmempool()
 
         # One more test, this time using height locks
         tx4 = test_nonzero_locks(
             tx3, self.nodes[0], use_height_lock=True)
-        assert(tx4.hash in self.nodes[0].getrawmempool())
+        assert tx4.hash in self.nodes[0].getrawmempool()
 
         # Now try combining confirmed and unconfirmed inputs
         tx5 = test_nonzero_locks(
             tx4, self.nodes[0], use_height_lock=True)
-        assert(tx5.hash not in self.nodes[0].getrawmempool())
+        assert tx5.hash not in self.nodes[0].getrawmempool()
 
         utxos = self.nodes[0].listunspent()
         tx5.vin.append(
@@ -369,8 +369,8 @@
         # If we invalidate the tip, tx3 should get added to the mempool, causing
         # tx4 to be removed (fails sequence-lock).
         self.nodes[0].invalidateblock(self.nodes[0].getbestblockhash())
-        assert(tx4.hash not in self.nodes[0].getrawmempool())
-        assert(tx3.hash in self.nodes[0].getrawmempool())
+        assert tx4.hash not in self.nodes[0].getrawmempool()
+        assert tx3.hash in self.nodes[0].getrawmempool()
 
         # Now mine 2 empty blocks to reorg out the current tip (labeled tip-1 in
         # diagram above).
@@ -390,8 +390,8 @@
             cur_time += 1
 
         mempool = self.nodes[0].getrawmempool()
-        assert(tx3.hash not in mempool)
-        assert(tx2.hash in mempool)
+        assert tx3.hash not in mempool
+        assert tx2.hash in mempool
 
         # Reset the chain and get rid of the mocktimed-blocks
         self.nodes[0].setmocktime(0)
@@ -486,9 +486,9 @@
             "hex"]
         try:
             self.nodes[1].sendrawtransaction(tx_signed)
-            assert(before_activation == False)
+            assert before_activation == False
         except:
-            assert(before_activation)
+            assert before_activation
 
 
 if __name__ == '__main__':
diff --git a/test/functional/feature_block.py b/test/functional/feature_block.py
--- a/test/functional/feature_block.py
+++ b/test/functional/feature_block.py
@@ -782,7 +782,7 @@
         self.move_tip(57)
         b58 = self.next_block(58, spend=out[17])
         tx = CTransaction()
-        assert(len(out[17].tx.vout) < 42)
+        assert len(out[17].tx.vout) < 42
         tx.vin.append(
             CTxIn(COutPoint(out[17].tx.sha256, 42), CScript([OP_TRUE]), 0xffffffff))
         tx.vout.append(CTxOut(0, b""))
@@ -840,11 +840,11 @@
         b62 = self.next_block(62)
         tx = CTransaction()
         tx.nLockTime = 0xffffffff  # this locktime is non-final
-        assert(out[18].n < len(out[18].tx.vout))
+        assert out[18].n < len(out[18].tx.vout)
         # don't set nSequence
         tx.vin.append(CTxIn(COutPoint(out[18].tx.sha256, out[18].n)))
         tx.vout.append(CTxOut(0, CScript([OP_TRUE])))
-        assert(tx.vin[0].nSequence < 0xffffffff)
+        assert tx.vin[0].nSequence < 0xffffffff
         tx.calc_sha256()
         b62 = self.update_block(62, [tx])
         self.sync_blocks([b62], success=False,
@@ -1186,8 +1186,8 @@
         # mempool
         mempool = self.nodes[0].getrawmempool()
         assert_equal(len(mempool), 2)
-        assert(tx78.hash in mempool)
-        assert(tx79.hash in mempool)
+        assert tx78.hash in mempool
+        assert tx79.hash in mempool
 
         # Test invalid opcodes in dead execution paths.
         #
diff --git a/test/functional/feature_cltv.py b/test/functional/feature_cltv.py
--- a/test/functional/feature_cltv.py
+++ b/test/functional/feature_cltv.py
@@ -175,7 +175,7 @@
             ToHex(spendtx))
 
         # Couldn't complete signature due to CLTV
-        assert(rejectedtx_signed['errors'][0]['error'] == 'Negative locktime')
+        assert rejectedtx_signed['errors'][0]['error'] == 'Negative locktime'
 
         tip = block.hash
         block_time += 1
diff --git a/test/functional/feature_csv_activation.py b/test/functional/feature_csv_activation.py
--- a/test/functional/feature_csv_activation.py
+++ b/test/functional/feature_csv_activation.py
@@ -137,7 +137,7 @@
 def create_bip68txs(node, bip68inputs, txversion, address, locktime_delta=0):
     """Returns a list of bip68 transactions with different bits set."""
     txs = []
-    assert(len(bip68inputs) >= 16)
+    assert len(bip68inputs) >= 16
     for i, (sdf, srhb, stf, srlb) in enumerate(product(*[[True, False]] * 4)):
         locktime = relative_locktime(sdf, srhb, stf, srlb)
         tx = create_transaction(
@@ -154,7 +154,7 @@
 def create_bip112txs(node, bip112inputs, varyOP_CSV, txversion, address, locktime_delta=0):
     """Returns a list of bip112 transactions with different bits set."""
     txs = []
-    assert(len(bip112inputs) >= 16)
+    assert len(bip112inputs) >= 16
     for i, (sdf, srhb, stf, srlb) in enumerate(product(*[[True, False]] * 4)):
         locktime = relative_locktime(sdf, srhb, stf, srlb)
         tx = create_transaction(
diff --git a/test/functional/feature_nulldummy.py b/test/functional/feature_nulldummy.py
--- a/test/functional/feature_nulldummy.py
+++ b/test/functional/feature_nulldummy.py
@@ -35,7 +35,7 @@
     newscript = []
     for i in scriptSig:
         if (len(newscript) == 0):
-            assert(len(i) == 0)
+            assert len(i) == 0
             newscript.append(b'\x51')
         else:
             newscript.append(i)
diff --git a/test/functional/feature_proxy.py b/test/functional/feature_proxy.py
--- a/test/functional/feature_proxy.py
+++ b/test/functional/feature_proxy.py
@@ -110,7 +110,7 @@
         # Test: outgoing IPv4 connection through node
         node.addnode("15.61.23.23:1234", "onetry")
         cmd = proxies[0].queue.get()
-        assert(isinstance(cmd, Socks5Command))
+        assert isinstance(cmd, Socks5Command)
         # Note: bitcoind's SOCKS5 implementation only sends atyp DOMAINNAME,
         # even if connecting directly to IPv4/IPv6
         assert_equal(cmd.atyp, AddressType.DOMAINNAME)
@@ -126,7 +126,7 @@
             node.addnode(
                 "[1233:3432:2434:2343:3234:2345:6546:4534]:5443", "onetry")
             cmd = proxies[1].queue.get()
-            assert(isinstance(cmd, Socks5Command))
+            assert isinstance(cmd, Socks5Command)
             # Note: bitcoind's SOCKS5 implementation only sends atyp
             # DOMAINNAME, even if connecting directly to IPv4/IPv6
             assert_equal(cmd.atyp, AddressType.DOMAINNAME)
@@ -141,7 +141,7 @@
             # Test: outgoing onion connection through node
             node.addnode("bitcoinostk4e4re.onion:8333", "onetry")
             cmd = proxies[2].queue.get()
-            assert(isinstance(cmd, Socks5Command))
+            assert isinstance(cmd, Socks5Command)
             assert_equal(cmd.atyp, AddressType.DOMAINNAME)
             assert_equal(cmd.addr, b"bitcoinostk4e4re.onion")
             assert_equal(cmd.port, 8333)
@@ -153,7 +153,7 @@
         # Test: outgoing DNS name connection through node
         node.addnode("node.noumenon:8333", "onetry")
         cmd = proxies[3].queue.get()
-        assert(isinstance(cmd, Socks5Command))
+        assert isinstance(cmd, Socks5Command)
         assert_equal(cmd.atyp, AddressType.DOMAINNAME)
         assert_equal(cmd.addr, b"node.noumenon")
         assert_equal(cmd.port, 8333)
diff --git a/test/functional/feature_pruning.py b/test/functional/feature_pruning.py
--- a/test/functional/feature_pruning.py
+++ b/test/functional/feature_pruning.py
@@ -175,7 +175,7 @@
             self.nodes[1].invalidateblock(curhash)
             curhash = self.nodes[1].getblockhash(invalidheight - 1)
 
-        assert(self.nodes[1].getblockcount() == invalidheight - 1)
+        assert self.nodes[1].getblockcount() == invalidheight - 1
         self.log.info("New best height: {}".format(
                       self.nodes[1].getblockcount()))
 
@@ -254,8 +254,8 @@
                 "Rewind node 0 to prev main chain to mine longer chain to trigger redownload. Blocks needed: {}".format(
                     blocks_to_mine))
             self.nodes[0].invalidateblock(curchainhash)
-            assert(self.nodes[0].getblockcount() == self.mainchainheight)
-            assert(self.nodes[0].getbestblockhash() == self.mainchainhash2)
+            assert self.nodes[0].getblockcount() == self.mainchainheight
+            assert self.nodes[0].getbestblockhash() == self.mainchainhash2
             goalbesthash = self.nodes[0].generate(blocks_to_mine)[-1]
             goalbestheight = first_reorg_height + 1
 
@@ -264,10 +264,10 @@
         # Wait for Node 2 to reorg to proper height
         wait_until(lambda: self.nodes[2].getblockcount(
         ) >= goalbestheight, timeout=900)
-        assert(self.nodes[2].getbestblockhash() == goalbesthash)
+        assert self.nodes[2].getbestblockhash() == goalbesthash
         # Verify we can now have the data for a block previously pruned
-        assert(self.nodes[2].getblock(
-            self.forkhash)["height"] == self.forkheight)
+        assert self.nodes[2].getblock(
+            self.forkhash)["height"] == self.forkheight
 
     def manual_test(self, node_number, use_timestamp):
         # at this point, node has 995 blocks and has not yet run in prune mode
diff --git a/test/functional/interface_bitcoin_cli.py b/test/functional/interface_bitcoin_cli.py
--- a/test/functional/interface_bitcoin_cli.py
+++ b/test/functional/interface_bitcoin_cli.py
@@ -21,7 +21,7 @@
         """Main test logic"""
 
         cli_response = self.nodes[0].cli("-version").send_cli()
-        assert("Bitcoin ABC RPC client version" in cli_response)
+        assert "Bitcoin ABC RPC client version" in cli_response
 
         self.log.info(
             "Compare responses from gewalletinfo RPC and `bitcoin-cli getwalletinfo`")
diff --git a/test/functional/interface_http.py b/test/functional/interface_http.py
--- a/test/functional/interface_http.py
+++ b/test/functional/interface_http.py
@@ -32,16 +32,16 @@
         conn.connect()
         conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
         out1 = conn.getresponse().read()
-        assert(b'"error":null' in out1)
-        assert(conn.sock != None)
+        assert b'"error":null' in out1
+        assert conn.sock != None
         # according to http/1.1 connection must still be open!
 
         # send 2nd request without closing connection
         conn.request('POST', '/', '{"method": "getchaintips"}', headers)
         out1 = conn.getresponse().read()
-        assert(b'"error":null' in out1)
+        assert b'"error":null' in out1
         # must also response with a correct json-rpc message
-        assert(conn.sock != None)
+        assert conn.sock != None
         # according to http/1.1 connection must still be open!
         conn.close()
 
@@ -54,16 +54,16 @@
         conn.connect()
         conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
         out1 = conn.getresponse().read()
-        assert(b'"error":null' in out1)
-        assert(conn.sock != None)
+        assert b'"error":null' in out1
+        assert conn.sock != None
         # according to http/1.1 connection must still be open!
 
         # send 2nd request without closing connection
         conn.request('POST', '/', '{"method": "getchaintips"}', headers)
         out1 = conn.getresponse().read()
-        assert(b'"error":null' in out1)
+        assert b'"error":null' in out1
         # must also response with a correct json-rpc message
-        assert(conn.sock != None)
+        assert conn.sock != None
         # according to http/1.1 connection must still be open!
         conn.close()
 
@@ -75,8 +75,8 @@
         conn.connect()
         conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
         out1 = conn.getresponse().read()
-        assert(b'"error":null' in out1)
-        assert(conn.sock == None)
+        assert b'"error":null' in out1
+        assert conn.sock == None
         # now the connection must be closed after the response
 
         # node1 (2nd node) is running with disabled keep-alive option
@@ -88,7 +88,7 @@
         conn.connect()
         conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
         out1 = conn.getresponse().read()
-        assert(b'"error":null' in out1)
+        assert b'"error":null' in out1
 
         # node2 (third node) is running with standard keep-alive parameters
         # which means keep-alive is on
@@ -100,8 +100,8 @@
         conn.connect()
         conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
         out1 = conn.getresponse().read()
-        assert(b'"error":null' in out1)
-        assert(conn.sock != None)
+        assert b'"error":null' in out1
+        assert conn.sock != None
         # connection must be closed because bitcoind should use
         # keep-alive by default
 
@@ -133,7 +133,7 @@
         assert_equal(out1.headers["Access-Control-Allow-Credentials"], "true")
         assert_equal(out1.headers["Access-Control-Expose-Headers"],
                      "WWW-Authenticate")
-        assert(b'"error":null' in out1.read())
+        assert b'"error":null' in out1.read()
 
         # Check Pre-flight CORS request
         corsheaders = {"Origin": origin,
diff --git a/test/functional/mempool_limit.py b/test/functional/mempool_limit.py
--- a/test/functional/mempool_limit.py
+++ b/test/functional/mempool_limit.py
@@ -57,9 +57,10 @@
                 self.nodes[0], utxos[30 * i:30 * i + 30], 30, 10 * (i + 1))
 
         self.log.info('The tx should be evicted by now')
-        assert(txid not in self.nodes[0].getrawmempool())
+        assert txid not in self.nodes[0].getrawmempool()
         txdata = self.nodes[0].gettransaction(txid)
-        assert(txdata['confirmations'] == 0)  # confirmation should still be 0
+        # confirmation should still be 0
+        assert txdata['confirmations'] == 0
 
         self.log.info('Check that mempoolminfee is larger than minrelytxfee')
         assert_equal(self.nodes[0].getmempoolinfo()[
diff --git a/test/functional/mempool_packages.py b/test/functional/mempool_packages.py
--- a/test/functional/mempool_packages.py
+++ b/test/functional/mempool_packages.py
@@ -39,7 +39,7 @@
         txid = node.sendrawtransaction(signedtx['hex'])
         fulltx = node.getrawtransaction(txid, 1)
         # make sure we didn't generate a change output
-        assert(len(fulltx['vout']) == num_outputs)
+        assert len(fulltx['vout']) == num_outputs
         return (txid, send_value)
 
     def run_test(self):
@@ -138,13 +138,13 @@
         assert_equal(len(v_ancestors), len(chain) - 1)
         for x in v_ancestors.keys():
             assert_equal(mempool[x], v_ancestors[x])
-        assert(chain[-1] not in v_ancestors.keys())
+        assert chain[-1] not in v_ancestors.keys()
 
         v_descendants = self.nodes[0].getmempooldescendants(chain[0], True)
         assert_equal(len(v_descendants), len(chain) - 1)
         for x in v_descendants.keys():
             assert_equal(mempool[x], v_descendants[x])
-        assert(chain[0] not in v_descendants.keys())
+        assert chain[0] not in v_descendants.keys()
 
         # Check that ancestor modified fees includes fee deltas from
         # prioritisetransaction
diff --git a/test/functional/mempool_resurrect.py b/test/functional/mempool_resurrect.py
--- a/test/functional/mempool_resurrect.py
+++ b/test/functional/mempool_resurrect.py
@@ -48,7 +48,7 @@
         assert_equal(set(self.nodes[0].getrawmempool()), set())
         for txid in spends1_id + spends2_id:
             tx = self.nodes[0].gettransaction(txid)
-            assert(tx["confirmations"] > 0)
+            assert tx["confirmations"] > 0
 
         # Use invalidateblock to re-org back; all transactions should
         # end up unconfirmed and back in the mempool
@@ -60,7 +60,7 @@
             set(self.nodes[0].getrawmempool()), set(spends1_id + spends2_id))
         for txid in spends1_id + spends2_id:
             tx = self.nodes[0].gettransaction(txid)
-            assert(tx["confirmations"] == 0)
+            assert tx["confirmations"] == 0
 
         # Generate another block, they should all get mined
         self.nodes[0].generate(1)
@@ -68,7 +68,7 @@
         assert_equal(set(self.nodes[0].getrawmempool()), set())
         for txid in spends1_id + spends2_id:
             tx = self.nodes[0].gettransaction(txid)
-            assert(tx["confirmations"] > 0)
+            assert tx["confirmations"] > 0
 
 
 if __name__ == '__main__':
diff --git a/test/functional/mining_getblocktemplate_longpoll.py b/test/functional/mining_getblocktemplate_longpoll.py
--- a/test/functional/mining_getblocktemplate_longpoll.py
+++ b/test/functional/mining_getblocktemplate_longpoll.py
@@ -40,7 +40,7 @@
         # longpollid should not change between successive invocations if
         # nothing else happens
         templat2 = self.nodes[0].getblocktemplate()
-        assert(templat2['longpollid'] == longpollid)
+        assert templat2['longpollid'] == longpollid
 
         # Test 1: test that the longpolling wait if we do nothing
         thr = LongpollThread(self.nodes[0])
@@ -48,7 +48,7 @@
         # check that thread still lives
         # wait 5 seconds or until thread exits
         thr.join(5)
-        assert(thr.is_alive())
+        assert thr.is_alive()
 
         # Test 2: test that longpoll will terminate if another node generates a block
         # generate a block on another node
@@ -56,7 +56,7 @@
         # check that thread will exit now that new transaction entered mempool
         # wait 5 seconds or until thread exits
         thr.join(5)
-        assert(not thr.is_alive())
+        assert not thr.is_alive()
 
         # Test 3: test that longpoll will terminate if we generate a block
         # ourselves
@@ -66,7 +66,7 @@
         self.nodes[0].generate(1)
         # wait 5 seconds or until thread exits
         thr.join(5)
-        assert(not thr.is_alive())
+        assert not thr.is_alive()
 
         # Test 4: test that introducing a new transaction into the mempool will
         # terminate the longpoll
@@ -80,7 +80,7 @@
         # after one minute, every 10 seconds the mempool is probed, so in 80
         # seconds it should have returned
         thr.join(60 + 20)
-        assert(not thr.is_alive())
+        assert not thr.is_alive()
 
 
 if __name__ == '__main__':
diff --git a/test/functional/mining_prioritisetransaction.py b/test/functional/mining_prioritisetransaction.py
--- a/test/functional/mining_prioritisetransaction.py
+++ b/test/functional/mining_prioritisetransaction.py
@@ -46,10 +46,10 @@
         sizes = [0, 0, 0]
         for i in range(3):
             for j in txids[i]:
-                assert(j in mempool)
+                assert j in mempool
                 sizes[i] += mempool[j]['size']
             # Fail => raise utxo_count
-            assert(sizes[i] > LEGACY_MAX_BLOCK_SIZE)
+            assert sizes[i] > LEGACY_MAX_BLOCK_SIZE
 
         # add a fee delta to something in the cheapest bucket and make sure it gets mined
         # also check that a different entry in the cheapest bucket is NOT mined (lower
@@ -62,8 +62,8 @@
 
         mempool = self.nodes[0].getrawmempool()
         self.log.info("Assert that prioritised transaction was mined")
-        assert(txids[0][0] not in mempool)
-        assert(txids[0][1] in mempool)
+        assert txids[0][0] not in mempool
+        assert txids[0][1] in mempool
 
         confirmed_transactions = self.nodes[0].getblock(
             self.nodes[0].getbestblockhash())['tx']
@@ -72,7 +72,7 @@
         high_fee_tx = confirmed_transactions[1]
 
         # Something high-fee should have been mined!
-        assert(high_fee_tx != None)
+        assert high_fee_tx != None
 
         # Add a prioritisation before a tx is in the mempool (de-prioritising a
         # high-fee transaction so that it's now low fee).
@@ -91,7 +91,7 @@
 
         # Check to make sure our high fee rate tx is back in the mempool
         mempool = self.nodes[0].getrawmempool()
-        assert(high_fee_tx in mempool)
+        assert high_fee_tx in mempool
 
         # Now verify the modified-high feerate transaction isn't mined before
         # the other high fee transactions. Keep mining until our mempool has
@@ -104,14 +104,14 @@
         mempool = self.nodes[0].getrawmempool()
         self.log.info(
             "Assert that de-prioritised transaction is still in mempool")
-        assert(high_fee_tx in mempool)
+        assert high_fee_tx in mempool
         for x in txids[2]:
             if (x != high_fee_tx):
-                assert(x not in mempool)
+                assert x not in mempool
 
         # Create a free, low priority transaction.  Should be rejected.
         utxo_list = self.nodes[0].listunspent()
-        assert(len(utxo_list) > 0)
+        assert len(utxo_list) > 0
         utxo = utxo_list[0]
 
         inputs = []
@@ -136,7 +136,7 @@
         # This will raise an exception due to min relay fee not being met
         assert_raises_rpc_error(-26, "insufficient priority (code 66)",
                                 self.nodes[0].sendrawtransaction, tx2_hex)
-        assert(tx2_id not in self.nodes[0].getrawmempool())
+        assert tx2_id not in self.nodes[0].getrawmempool()
 
         # This is a less than 1000-byte transaction, so just set the fee
         # to be the minimum for a 1000-byte transaction and check that it is
@@ -147,7 +147,7 @@
         self.log.info(
             "Assert that prioritised free transaction is accepted to mempool")
         assert_equal(self.nodes[0].sendrawtransaction(tx2_hex), tx2_id)
-        assert(tx2_id in self.nodes[0].getrawmempool())
+        assert tx2_id in self.nodes[0].getrawmempool()
 
         # Test that calling prioritisetransaction is sufficient to trigger
         # getblocktemplate to (eventually) return a new block.
@@ -159,7 +159,7 @@
         self.nodes[0].setmocktime(mock_time + 10)
         new_template = self.nodes[0].getblocktemplate()
 
-        assert(template != new_template)
+        assert template != new_template
 
 
 if __name__ == '__main__':
diff --git a/test/functional/p2p_compactblocks.py b/test/functional/p2p_compactblocks.py
--- a/test/functional/p2p_compactblocks.py
+++ b/test/functional/p2p_compactblocks.py
@@ -151,7 +151,7 @@
         # Doesn't matter which node we use, just use node0.
         block = self.build_block_on_tip(self.nodes[0])
         self.test_node.send_and_ping(msg_block(block))
-        assert(int(self.nodes[0].getbestblockhash(), 16) == block.sha256)
+        assert int(self.nodes[0].getbestblockhash(), 16) == block.sha256
         self.nodes[0].generate(100)
 
         total_value = block.vtx[0].vout[0].nValue
@@ -199,7 +199,7 @@
             peer.clear_block_announcement()
             block_hash = int(node.generate(1)[0], 16)
             peer.wait_for_block_announcement(block_hash, timeout=30)
-            assert(peer.block_announced)
+            assert peer.block_announced
 
             with mininode_lock:
                 assert predicate(peer), (
@@ -336,7 +336,7 @@
         # Now fetch and check the compact block
         header_and_shortids = None
         with mininode_lock:
-            assert("cmpctblock" in test_node.last_message)
+            assert "cmpctblock" in test_node.last_message
             # Convert the on-the-wire representation to absolute indexes
             header_and_shortids = HeaderAndShortIDs(
                 test_node.last_message["cmpctblock"].header_and_shortids)
@@ -355,7 +355,7 @@
         # Now fetch and check the compact block
         header_and_shortids = None
         with mininode_lock:
-            assert("cmpctblock" in test_node.last_message)
+            assert "cmpctblock" in test_node.last_message
             # Convert the on-the-wire representation to absolute indexes
             header_and_shortids = HeaderAndShortIDs(
                 test_node.last_message["cmpctblock"].header_and_shortids)
@@ -368,7 +368,7 @@
         assert_equal(header_and_shortids.header.sha256, block_hash)
 
         # Make sure the prefilled_txn appears to have included the coinbase
-        assert(len(header_and_shortids.prefilled_txn) >= 1)
+        assert len(header_and_shortids.prefilled_txn) >= 1
         assert_equal(header_and_shortids.prefilled_txn[0].index, 0)
 
         # Check that all prefilled_txn entries match what's in the block.
@@ -435,7 +435,7 @@
             assert_equal(int(node.getbestblockhash(), 16), block.hashPrevBlock)
             # Expect a getblocktxn message.
             with mininode_lock:
-                assert("getblocktxn" in test_node.last_message)
+                assert "getblocktxn" in test_node.last_message
                 absolute_indexes = test_node.last_message["getblocktxn"].block_txn_request.to_absolute(
                 )
             assert_equal(absolute_indexes, [0])  # should be a coinbase request
@@ -477,7 +477,7 @@
             msg = msg_cmpctblock(compact_block.to_p2p())
             peer.send_and_ping(msg)
             with mininode_lock:
-                assert("getblocktxn" in peer.last_message)
+                assert "getblocktxn" in peer.last_message
                 absolute_indexes = peer.last_message["getblocktxn"].block_txn_request.to_absolute(
                 )
             assert_equal(absolute_indexes, expected_result)
@@ -522,7 +522,7 @@
         self.utxos.append(
             [ordered_txs[-1].sha256, 0, ordered_txs[-1].vout[0].nValue])
         test_node.send_and_ping(msg_tx(ordered_txs[1]))
-        assert(ordered_txs[1].hash in node.getrawmempool())
+        assert ordered_txs[1].hash in node.getrawmempool()
         test_node.send_and_ping(msg_tx(ordered_txs[1]))
 
         # Prefill 4 out of the 6 transactions, and verify that only the one
@@ -550,7 +550,7 @@
         # Make sure all transactions were accepted.
         mempool = node.getrawmempool()
         for tx in block.vtx[1:]:
-            assert(tx.hash in mempool)
+            assert tx.hash in mempool
 
         # Clear out last request.
         with mininode_lock:
@@ -562,7 +562,7 @@
             node, test_node, msg_cmpctblock(comp_block.to_p2p()), block.sha256)
         with mininode_lock:
             # Shouldn't have gotten a request for any transaction
-            assert("getblocktxn" not in test_node.last_message)
+            assert "getblocktxn" not in test_node.last_message
 
     # Incorrectly responding to a getblocktxn shouldn't cause the block to be
     # permanently failed.
@@ -581,7 +581,7 @@
         # Make sure all transactions were accepted.
         mempool = node.getrawmempool()
         for tx in ordered_txs[1:6]:
-            assert(tx.hash in mempool)
+            assert tx.hash in mempool
 
         # Send compact block
         comp_block = HeaderAndShortIDs()
@@ -589,7 +589,7 @@
         test_node.send_and_ping(msg_cmpctblock(comp_block.to_p2p()))
         absolute_indices = []
         with mininode_lock:
-            assert("getblocktxn" in test_node.last_message)
+            assert "getblocktxn" in test_node.last_message
             absolute_indices = test_node.last_message["getblocktxn"].block_txn_request.to_absolute(
             )
         expected_indices = []
@@ -617,7 +617,7 @@
         wait_until(lambda: "getdata" in test_node.last_message,
                    timeout=10, lock=mininode_lock)
         assert_equal(len(test_node.last_message["getdata"].inv), 1)
-        assert(test_node.last_message["getdata"].inv[0].type == 2)
+        assert test_node.last_message["getdata"].inv[0].type == 2
         assert_equal(
             test_node.last_message["getdata"].inv[0].hash, block.sha256)
 
@@ -721,7 +721,7 @@
                 assert_equal(x["status"], "headers-only")
                 found = True
                 break
-        assert(found)
+        assert found
 
         # Requesting this block via getblocktxn should silently fail
         # (to avoid fingerprinting attacks).
@@ -756,7 +756,7 @@
     # Test that we don't get disconnected if we relay a compact block with valid header,
     # but invalid transactions.
     def test_invalid_tx_in_compactblock(self, node, test_node):
-        assert(len(self.utxos))
+        assert len(self.utxos)
         utxo = self.utxos[0]
 
         block, ordered_txs = self.build_block_with_transactions(node, utxo, 5)
@@ -772,7 +772,7 @@
         test_node.send_and_ping(msg)
 
         # Check that the tip didn't advance
-        assert(int(node.getbestblockhash(), 16) is not block.sha256)
+        assert int(node.getbestblockhash(), 16) is not block.sha256
         test_node.sync_with_ping()
 
     # Helper for enabling cb announcements
@@ -787,7 +787,7 @@
         peer.send_and_ping(msg)
 
     def test_compactblock_reconstruction_multiple_peers(self, node, stalling_peer, delivery_peer):
-        assert(len(self.utxos))
+        assert len(self.utxos)
 
         def announce_cmpct_block(node, peer):
             utxo = self.utxos.pop(0)
@@ -808,7 +808,7 @@
         delivery_peer.sync_with_ping()
         mempool = node.getrawmempool()
         for tx in block.vtx[1:]:
-            assert(tx.hash in mempool)
+            assert tx.hash in mempool
 
         delivery_peer.send_and_ping(msg_cmpctblock(cmpct_block.to_p2p()))
         assert_equal(int(node.getbestblockhash(), 16), block.sha256)
@@ -825,7 +825,7 @@
         # TODO: modify txhash in a way that doesn't impact txid.
         delivery_peer.send_and_ping(msg_cmpctblock(cmpct_block.to_p2p()))
         # Because txhash isn't modified, we end up reconstructing the same block
-        # assert(int(node.getbestblockhash(), 16) != block.sha256)
+        # assert int(node.getbestblockhash(), 16) != block.sha256
 
         msg = msg_blocktxn()
         msg.block_transactions.blockhash = block.sha256
diff --git a/test/functional/p2p_feefilter.py b/test/functional/p2p_feefilter.py
--- a/test/functional/p2p_feefilter.py
+++ b/test/functional/p2p_feefilter.py
@@ -63,7 +63,7 @@
         node1.settxfee(Decimal("0.00020000"))
         txids = [node1.sendtoaddress(node1.getnewaddress(), 1)
                  for x in range(3)]
-        assert(allInvsMatch(txids, self.nodes[0].p2p))
+        assert allInvsMatch(txids, self.nodes[0].p2p)
         self.nodes[0].p2p.clear_invs()
 
         # Set a filter of 15 sat/byte
@@ -72,7 +72,7 @@
         # Test that txs are still being received (paying 20 sat/byte)
         txids = [node1.sendtoaddress(node1.getnewaddress(), 1)
                  for x in range(3)]
-        assert(allInvsMatch(txids, self.nodes[0].p2p))
+        assert allInvsMatch(txids, self.nodes[0].p2p)
         self.nodes[0].p2p.clear_invs()
 
         # Change tx fee rate to 10 sat/byte and test they are no longer
@@ -90,14 +90,14 @@
         # as well.
         node0.settxfee(Decimal("0.00020000"))
         txids = [node0.sendtoaddress(node0.getnewaddress(), 1)]
-        assert(allInvsMatch(txids, self.nodes[0].p2p))
+        assert allInvsMatch(txids, self.nodes[0].p2p)
         self.nodes[0].p2p.clear_invs()
 
         # Remove fee filter and check that txs are received again
         self.nodes[0].p2p.send_and_ping(msg_feefilter(0))
         txids = [node1.sendtoaddress(node1.getnewaddress(), 1)
                  for x in range(3)]
-        assert(allInvsMatch(txids, self.nodes[0].p2p))
+        assert allInvsMatch(txids, self.nodes[0].p2p)
         self.nodes[0].p2p.clear_invs()
 
 
diff --git a/test/functional/p2p_invalid_block.py b/test/functional/p2p_invalid_block.py
--- a/test/functional/p2p_invalid_block.py
+++ b/test/functional/p2p_invalid_block.py
@@ -85,7 +85,7 @@
         block2.vtx.append(block2.vtx[2])
         assert_equal(block2.hashMerkleRoot, block2.calc_merkle_root())
         assert_equal(orig_hash, block2.rehash())
-        assert(block2_orig.vtx != block2.vtx)
+        assert block2_orig.vtx != block2.vtx
 
         node.p2p.send_blocks_and_test(
             [block2], node, success=False, request_block=False, reject_reason='bad-txns-duplicate')
diff --git a/test/functional/p2p_leak.py b/test/functional/p2p_leak.py
--- a/test/functional/p2p_leak.py
+++ b/test/functional/p2p_leak.py
@@ -162,9 +162,9 @@
         wait_until(lambda: len(self.nodes[0].getpeerinfo()) == 0)
 
         # Make sure no unexpected messages came in
-        assert(no_version_bannode.unexpected_msg == False)
-        assert(no_version_idlenode.unexpected_msg == False)
-        assert(no_verack_idlenode.unexpected_msg == False)
+        assert no_version_bannode.unexpected_msg == False
+        assert no_version_idlenode.unexpected_msg == False
+        assert no_verack_idlenode.unexpected_msg == False
 
 
 if __name__ == '__main__':
diff --git a/test/functional/p2p_unrequested_blocks.py b/test/functional/p2p_unrequested_blocks.py
--- a/test/functional/p2p_unrequested_blocks.py
+++ b/test/functional/p2p_unrequested_blocks.py
@@ -138,7 +138,7 @@
             if x['hash'] == block_h1f.hash:
                 assert_equal(x['status'], "headers-only")
                 tip_entry_found = True
-        assert(tip_entry_found)
+        assert tip_entry_found
         assert_raises_rpc_error(-1, "Block not found on disk",
                                 self.nodes[0].getblock, block_h1f.hash)
 
@@ -157,7 +157,7 @@
             if x['hash'] == block_h2f.hash:
                 assert_equal(x['status'], "headers-only")
                 tip_entry_found = True
-        assert(tip_entry_found)
+        assert tip_entry_found
 
         # But this block should be accepted by node since it has equal work.
         self.nodes[0].getblock(block_h2f.hash)
@@ -177,7 +177,7 @@
             if x['hash'] == block_h3.hash:
                 assert_equal(x['status'], "headers-only")
                 tip_entry_found = True
-        assert(tip_entry_found)
+        assert tip_entry_found
         self.nodes[0].getblock(block_h3.hash)
 
         # But this block should be accepted by node since it has more work.
@@ -301,7 +301,7 @@
             if x['hash'] == block_292.hash:
                 assert_equal(x['status'], "headers-only")
                 tip_entry_found = True
-        assert(tip_entry_found)
+        assert tip_entry_found
         assert_raises_rpc_error(-1, "Block not found on disk",
                                 self.nodes[0].getblock, block_292.hash)
 
diff --git a/test/functional/rpc_blockchain.py b/test/functional/rpc_blockchain.py
--- a/test/functional/rpc_blockchain.py
+++ b/test/functional/rpc_blockchain.py
@@ -169,9 +169,9 @@
         assert_equal(chaintxstats['txcount'], 2)
         assert_equal(chaintxstats['window_final_block_hash'], b1_hash)
         assert_equal(chaintxstats['window_block_count'], 0)
-        assert('window_tx_count' not in chaintxstats)
-        assert('window_interval' not in chaintxstats)
-        assert('txrate' not in chaintxstats)
+        assert 'window_tx_count' not in chaintxstats
+        assert 'window_interval' not in chaintxstats
+        assert 'txrate' not in chaintxstats
 
     def _test_gettxoutsetinfo(self):
         node = self.nodes[0]
diff --git a/test/functional/rpc_fundrawtransaction.py b/test/functional/rpc_fundrawtransaction.py
--- a/test/functional/rpc_fundrawtransaction.py
+++ b/test/functional/rpc_fundrawtransaction.py
@@ -101,7 +101,8 @@
         rawtxfund = self.nodes[2].fundrawtransaction(rawTx)
         fee = rawtxfund['fee']
         dec_tx = self.nodes[2].decoderawtransaction(rawtxfund['hex'])
-        assert(len(dec_tx['vin']) > 0)  # test that we have enough inputs
+        # test that we have enough inputs
+        assert len(dec_tx['vin']) > 0
 
         #
         # simple test with two coins #
@@ -114,7 +115,8 @@
         rawtxfund = self.nodes[2].fundrawtransaction(rawTx)
         fee = rawtxfund['fee']
         dec_tx = self.nodes[2].decoderawtransaction(rawtxfund['hex'])
-        assert(len(dec_tx['vin']) > 0)  # test if we have enough inputs
+        # test if we have enough inputs
+        assert len(dec_tx['vin']) > 0
 
         #
         # simple test with two coins #
@@ -127,7 +129,7 @@
         rawtxfund = self.nodes[2].fundrawtransaction(rawTx)
         fee = rawtxfund['fee']
         dec_tx = self.nodes[2].decoderawtransaction(rawtxfund['hex'])
-        assert(len(dec_tx['vin']) > 0)
+        assert len(dec_tx['vin']) > 0
         assert_equal(dec_tx['vin'][0]['scriptSig']['hex'], '')
 
         #
@@ -146,7 +148,7 @@
         for out in dec_tx['vout']:
             totalOut += out['value']
 
-        assert(len(dec_tx['vin']) > 0)
+        assert len(dec_tx['vin']) > 0
         assert_equal(dec_tx['vin'][0]['scriptSig']['hex'], '')
 
         #
@@ -364,7 +366,7 @@
 
         # compare fee
         feeDelta = Decimal(fundedTx['fee']) - Decimal(signedFee)
-        assert(feeDelta >= 0 and feeDelta <= feeTolerance)
+        assert feeDelta >= 0 and feeDelta <= feeTolerance
         #
 
         #
@@ -381,7 +383,7 @@
 
         # compare fee
         feeDelta = Decimal(fundedTx['fee']) - Decimal(signedFee)
-        assert(feeDelta >= 0 and feeDelta <= feeTolerance)
+        assert feeDelta >= 0 and feeDelta <= feeTolerance
         #
 
         #
@@ -408,7 +410,7 @@
 
         # compare fee
         feeDelta = Decimal(fundedTx['fee']) - Decimal(signedFee)
-        assert(feeDelta >= 0 and feeDelta <= feeTolerance)
+        assert feeDelta >= 0 and feeDelta <= feeTolerance
         #
 
         #
@@ -441,7 +443,7 @@
 
         # compare fee
         feeDelta = Decimal(fundedTx['fee']) - Decimal(signedFee)
-        assert(feeDelta >= 0 and feeDelta <= feeTolerance)
+        assert feeDelta >= 0 and feeDelta <= feeTolerance
         #
 
         #
@@ -569,7 +571,8 @@
 
         # compare fee
         feeDelta = Decimal(fundedTx['fee']) - Decimal(signedFee)
-        assert(feeDelta >= 0 and feeDelta <= feeTolerance * 19)  # ~19 inputs
+        # ~19 inputs
+        assert feeDelta >= 0 and feeDelta <= feeTolerance * 19
 
         #
         # multiple (~19) inputs tx test | sign/send #
@@ -634,7 +637,7 @@
         assert_equal(len(res_dec["vin"]), 1)
         assert_equal(res_dec["vin"][0]["txid"], watchonly_txid)
 
-        assert("fee" in result.keys())
+        assert "fee" in result.keys()
         assert_greater_than(result["changepos"], -1)
 
         #
@@ -649,8 +652,8 @@
         result = self.nodes[3].fundrawtransaction(rawTx, True)
         res_dec = self.nodes[0].decoderawtransaction(result["hex"])
         assert_equal(len(res_dec["vin"]), 2)
-        assert(res_dec["vin"][0]["txid"] == watchonly_txid or res_dec[
-               "vin"][1]["txid"] == watchonly_txid)
+        assert res_dec["vin"][0]["txid"] == watchonly_txid or res_dec[
+            "vin"][1]["txid"] == watchonly_txid
 
         assert_greater_than(result["fee"], 0)
         assert_greater_than(result["changepos"], -1)
@@ -658,9 +661,9 @@
                      result["changepos"]]["value"], watchonly_amount / 10)
 
         signedtx = self.nodes[3].signrawtransactionwithwallet(result["hex"])
-        assert(not signedtx["complete"])
+        assert not signedtx["complete"]
         signedtx = self.nodes[0].signrawtransactionwithwallet(signedtx["hex"])
-        assert(signedtx["complete"])
+        assert signedtx["complete"]
         self.nodes[0].sendrawtransaction(signedtx["hex"])
         self.nodes[0].generate(1)
         self.sync_all()
@@ -703,10 +706,10 @@
         for out in res_dec['vout']:
             if out['value'] > 1.0:
                 changeaddress += out['scriptPubKey']['addresses'][0]
-        assert(changeaddress != "")
+        assert changeaddress != ""
         nextaddr = self.nodes[3].getnewaddress()
         # Now the change address key should be removed from the keypool
-        assert(changeaddress != nextaddr)
+        assert changeaddress != nextaddr
 
         #
         # Test subtractFeeFromOutputs option #
diff --git a/test/functional/rpc_invalidateblock.py b/test/functional/rpc_invalidateblock.py
--- a/test/functional/rpc_invalidateblock.py
+++ b/test/functional/rpc_invalidateblock.py
@@ -24,17 +24,17 @@
             "Make sure we repopulate setBlockIndexCandidates after InvalidateBlock:")
         self.log.info("Mine 4 blocks on Node 0")
         self.nodes[0].generate(4)
-        assert(self.nodes[0].getblockcount() == 4)
+        assert self.nodes[0].getblockcount() == 4
         besthash = self.nodes[0].getbestblockhash()
 
         self.log.info("Mine competing 6 blocks on Node 1")
         self.nodes[1].generate(6)
-        assert(self.nodes[1].getblockcount() == 6)
+        assert self.nodes[1].getblockcount() == 6
 
         self.log.info("Connect nodes to force a reorg")
         connect_nodes_bi(self.nodes[0], self.nodes[1])
         sync_blocks(self.nodes[0:2])
-        assert(self.nodes[0].getblockcount() == 6)
+        assert self.nodes[0].getblockcount() == 6
         badhash = self.nodes[1].getblockhash(2)
 
         self.log.info(
@@ -50,13 +50,13 @@
         connect_nodes_bi(self.nodes[1], self.nodes[2])
         self.log.info("Sync node 2 to node 1 so both have 6 blocks")
         sync_blocks(self.nodes[1:3])
-        assert(self.nodes[2].getblockcount() == 6)
+        assert self.nodes[2].getblockcount() == 6
         self.log.info("Invalidate block 5 on node 1 so its tip is now at 4")
         self.nodes[1].invalidateblock(self.nodes[1].getblockhash(5))
-        assert(self.nodes[1].getblockcount() == 4)
+        assert self.nodes[1].getblockcount() == 4
         self.log.info("Invalidate block 3 on node 2, so its tip is now 2")
         self.nodes[2].invalidateblock(self.nodes[2].getblockhash(3))
-        assert(self.nodes[2].getblockcount() == 2)
+        assert self.nodes[2].getblockcount() == 2
         self.log.info("..and then mine a block")
         self.nodes[2].generate(1)
         self.log.info("Verify all nodes are at the right height")
diff --git a/test/functional/rpc_listtransactions.py b/test/functional/rpc_listtransactions.py
--- a/test/functional/rpc_listtransactions.py
+++ b/test/functional/rpc_listtransactions.py
@@ -85,8 +85,8 @@
         txid = self.nodes[1].sendtoaddress(multisig["address"], 0.1)
         self.nodes[1].generate(1)
         self.sync_all()
-        assert(
-            len(self.nodes[0].listtransactions("watchonly", 100, 0, False)) == 0)
+        assert len(self.nodes[0].listtransactions(
+            "watchonly", 100, 0, False)) == 0
         assert_array_result(
             self.nodes[0].listtransactions("watchonly", 100, 0, True),
             {"category": "receive", "amount": Decimal("0.1")},
diff --git a/test/functional/rpc_named_arguments.py b/test/functional/rpc_named_arguments.py
--- a/test/functional/rpc_named_arguments.py
+++ b/test/functional/rpc_named_arguments.py
@@ -15,7 +15,7 @@
     def run_test(self):
         node = self.nodes[0]
         h = node.help(command='getblockchaininfo')
-        assert(h.startswith('getblockchaininfo\n'))
+        assert h.startswith('getblockchaininfo\n')
 
         assert_raises_rpc_error(-8, 'Unknown named parameter',
                                 node.help, random='getblockchaininfo')
diff --git a/test/functional/rpc_preciousblock.py b/test/functional/rpc_preciousblock.py
--- a/test/functional/rpc_preciousblock.py
+++ b/test/functional/rpc_preciousblock.py
@@ -17,7 +17,7 @@
     blockhash = node_src.getbestblockhash()
     while True:
         try:
-            assert(len(node_dest.getblock(blockhash, False)) > 0)
+            assert len(node_dest.getblock(blockhash, False)) > 0
             break
         except:
             blocks_to_copy.append(blockhash)
@@ -26,7 +26,7 @@
     blocks_to_copy.reverse()
     for blockhash in blocks_to_copy:
         blockdata = node_src.getblock(blockhash, False)
-        assert(node_dest.submitblock(blockdata) in (None, 'inconclusive'))
+        assert node_dest.submitblock(blockdata) in (None, 'inconclusive')
 
 
 def node_sync_via_rpc(nodes):
@@ -63,7 +63,7 @@
         self.log.info("Mine competing blocks E-F-G on Node 1")
         hashG = self.nodes[1].generate(3)[-1]
         assert_equal(self.nodes[1].getblockcount(), 5)
-        assert(hashC != hashG)
+        assert hashC != hashG
         self.log.info("Connect nodes and check no reorg occurs")
         # Submit competing blocks via RPC so any reorg should occur before we
         # proceed (no way to wait on inaction for p2p sync)
diff --git a/test/functional/rpc_signmessage.py b/test/functional/rpc_signmessage.py
--- a/test/functional/rpc_signmessage.py
+++ b/test/functional/rpc_signmessage.py
@@ -22,20 +22,20 @@
         expected_signature = 'IPDOIFcWd8LzOr70CXaal4+uG2ZZWcbHqutyGeO7AJ0MWbqq9C+u3KP9ScjtLzsIgY3st5n8XFQvgMZ0KrDQ9vg='
         signature = self.nodes[0].signmessagewithprivkey(priv_key, message)
         assert_equal(expected_signature, signature)
-        assert(self.nodes[0].verifymessage(address, signature, message))
+        assert self.nodes[0].verifymessage(address, signature, message)
 
         self.log.info('test signing with an address with wallet')
         address = self.nodes[0].getnewaddress()
         signature = self.nodes[0].signmessage(address, message)
-        assert(self.nodes[0].verifymessage(address, signature, message))
+        assert self.nodes[0].verifymessage(address, signature, message)
 
         self.log.info('test verifying with another address should not work')
         other_address = self.nodes[0].getnewaddress()
         other_signature = self.nodes[0].signmessage(other_address, message)
-        assert(not self.nodes[0].verifymessage(
-            other_address, signature, message))
-        assert(not self.nodes[0].verifymessage(
-            address, other_signature, message))
+        assert not self.nodes[0].verifymessage(
+            other_address, signature, message)
+        assert not self.nodes[0].verifymessage(
+            address, other_signature, message)
 
 
 if __name__ == '__main__':
diff --git a/test/functional/rpc_uptime.py b/test/functional/rpc_uptime.py
--- a/test/functional/rpc_uptime.py
+++ b/test/functional/rpc_uptime.py
@@ -23,7 +23,7 @@
     def _test_uptime(self):
         wait_time = 10
         self.nodes[0].setmocktime(int(time.time() + wait_time))
-        assert(self.nodes[0].uptime() >= wait_time)
+        assert self.nodes[0].uptime() >= wait_time
 
 
 if __name__ == '__main__':
diff --git a/test/functional/test_framework/address.py b/test/functional/test_framework/address.py
--- a/test/functional/test_framework/address.py
+++ b/test/functional/test_framework/address.py
@@ -55,7 +55,7 @@
         key = hex_str_to_bytes(key)  # Assuming this is hex string
     if (type(key) is bytes and (len(key) == 33 or len(key) == 65)):
         return key
-    assert(False)
+    assert False
 
 
 def check_script(script):
@@ -63,4 +63,4 @@
         script = hex_str_to_bytes(script)  # Assuming this is hex string
     if (type(script) is bytes or type(script) is CScript):
         return script
-    assert(False)
+    assert False
diff --git a/test/functional/test_framework/blocktools.py b/test/functional/test_framework/blocktools.py
--- a/test/functional/test_framework/blocktools.py
+++ b/test/functional/test_framework/blocktools.py
@@ -98,7 +98,7 @@
 
 def create_transaction(prevtx, n, sig, value, scriptPubKey=CScript()):
     tx = CTransaction()
-    assert(n < len(prevtx.vout))
+    assert n < len(prevtx.vout)
     tx.vin.append(CTxIn(COutPoint(prevtx.sha256, n), sig, 0xffffffff))
     tx.vout.append(CTxOut(value, scriptPubKey))
     pad_tx(tx)
@@ -158,7 +158,7 @@
         node.generate(1)
 
     utxos = node.listunspent()
-    assert(len(utxos) >= count)
+    assert len(utxos) >= count
     return utxos
 
 
diff --git a/test/functional/test_framework/netutil.py b/test/functional/test_framework/netutil.py
--- a/test/functional/test_framework/netutil.py
+++ b/test/functional/test_framework/netutil.py
@@ -139,13 +139,13 @@
                 if i == 0 or i == (len(addr) - 1):
                     continue
                 x += 1  # :: skips to suffix
-                assert(x < 2)
+                assert x < 2
             else:  # two bytes per component
                 val = int(comp, 16)
                 sub[x].append(val >> 8)
                 sub[x].append(val & 0xff)
         nullbytes = 16 - len(sub[0]) - len(sub[1])
-        assert((x == 0 and nullbytes == 0) or (x == 1 and nullbytes > 0))
+        assert (x == 0 and nullbytes == 0) or (x == 1 and nullbytes > 0)
         addr = sub[0] + ([0] * nullbytes) + sub[1]
     else:
         raise ValueError('Could not parse address {}'.format(addr))
diff --git a/test/functional/test_framework/schnorr.py b/test/functional/test_framework/schnorr.py
--- a/test/functional/test_framework/schnorr.py
+++ b/test/functional/test_framework/schnorr.py
@@ -72,7 +72,7 @@
 
     def __init__(self):
         self.ptr = ssl.BN_CTX_new()
-        assert(self.ptr)
+        assert self.ptr
 
     def __del__(self):
         ssl.BN_CTX_free(self.ptr)
diff --git a/test/functional/test_framework/socks5.py b/test/functional/test_framework/socks5.py
--- a/test/functional/test_framework/socks5.py
+++ b/test/functional/test_framework/socks5.py
@@ -162,7 +162,7 @@
                 thread.start()
 
     def start(self):
-        assert(not self.running)
+        assert not self.running
         self.running = True
         self.thread = threading.Thread(None, self.run)
         self.thread.daemon = True
diff --git a/test/functional/test_framework/util.py b/test/functional/test_framework/util.py
--- a/test/functional/test_framework/util.py
+++ b/test/functional/test_framework/util.py
@@ -311,7 +311,7 @@
 
 
 def p2p_port(n):
-    assert(n <= MAX_NODES)
+    assert n <= MAX_NODES
     return PORT_MIN + n + (MAX_NODES * PortSeed.n) % (PORT_RANGE - 1 - MAX_NODES)
 
 
@@ -482,7 +482,7 @@
     """
     Return a random set of unspent txouts that are enough to pay amount_needed
     """
-    assert(confirmations_required >= 0)
+    assert confirmations_required >= 0
     utxo = from_node.listunspent(confirmations_required)
     random.shuffle(utxo)
     inputs = []
diff --git a/test/functional/wallet_abandonconflict.py b/test/functional/wallet_abandonconflict.py
--- a/test/functional/wallet_abandonconflict.py
+++ b/test/functional/wallet_abandonconflict.py
@@ -60,7 +60,7 @@
         newbalance = self.nodes[0].getbalance()
 
         # no more than fees lost
-        assert(balance - newbalance <= total_fees(txA, txB, txC))
+        assert balance - newbalance <= total_fees(txA, txB, txC)
         balance = newbalance
 
         # Disconnect nodes so node0's transactions don't get into node1's mempool
@@ -137,8 +137,8 @@
         assert_equal(unconfbalance, newbalance)
         # Unconfirmed transactions which are not in the mempool should also
         # not be in listunspent
-        assert(not txABC2 in [utxo["txid"]
-                              for utxo in self.nodes[0].listunspent(0)])
+        assert not txABC2 in [utxo["txid"]
+                              for utxo in self.nodes[0].listunspent(0)]
         balance = newbalance
 
         # Abandon original transaction and verify inputs are available again
diff --git a/test/functional/wallet_basic.py b/test/functional/wallet_basic.py
--- a/test/functional/wallet_basic.py
+++ b/test/functional/wallet_basic.py
@@ -89,8 +89,8 @@
         mempool_txid = self.nodes[0].sendtoaddress(
             self.nodes[2].getnewaddress(), 10)
         memory_after = self.nodes[0].getmemoryinfo()
-        assert(memory_before['locked']['used'] +
-               64 <= memory_after['locked']['used'])
+        assert memory_before['locked']['used'] + \
+            64 <= memory_after['locked']['used']
 
         self.log.info("test gettxout (second part)")
         # utxo spent in mempool should be visible if you exclude mempool
@@ -237,7 +237,7 @@
         assert_equal(set(relayed), {txid1, txid2})
         sync_mempools(self.nodes)
 
-        assert(txid1 in self.nodes[3].getrawmempool())
+        assert txid1 in self.nodes[3].getrawmempool()
 
         # Exercise balance rpcs
         assert_equal(self.nodes[0].getwalletinfo()["unconfirmed_balance"], 1)
@@ -272,7 +272,7 @@
             if uTx['txid'] == zeroValueTxid:
                 found = True
                 assert_equal(uTx['amount'], Decimal('0'))
-        assert(found)
+        assert found
 
         # do some -walletbroadcast tests
         self.stop_nodes()
@@ -356,7 +356,7 @@
         self.nodes[1].importaddress(address_to_import)
 
         # 3. Validate that the imported address is watch-only on node1
-        assert(self.nodes[1].getaddressinfo(address_to_import)["iswatchonly"])
+        assert self.nodes[1].getaddressinfo(address_to_import)["iswatchonly"]
 
         # 4. Check that the unspents after import are not spendable
         assert_array_result(self.nodes[1].listunspent(),
@@ -398,7 +398,7 @@
                 addr = self.nodes[0].getaccountaddress(s)
                 label = self.nodes[0].getaccount(addr)
                 assert_equal(label, s)
-                assert(s in self.nodes[0].listaccounts().keys())
+                assert s in self.nodes[0].listaccounts().keys()
         self.nodes[0].ensure_ascii = True  # restore to default
 
         # maintenance tests
@@ -465,9 +465,9 @@
         # The tx will be stored in the wallet but not accepted to the mempool
         extra_txid = self.nodes[0].sendtoaddress(
             sending_addr, Decimal('0.0001'))
-        assert(extra_txid not in self.nodes[0].getrawmempool())
-        assert(extra_txid in [tx["txid"]
-                              for tx in self.nodes[0].listtransactions()])
+        assert extra_txid not in self.nodes[0].getrawmempool()
+        assert extra_txid in [tx["txid"]
+                              for tx in self.nodes[0].listtransactions()]
         self.nodes[0].abandontransaction(extra_txid)
         total_txs = len(self.nodes[0].listtransactions("*", 99999))
 
diff --git a/test/functional/wallet_disable.py b/test/functional/wallet_disable.py
--- a/test/functional/wallet_disable.py
+++ b/test/functional/wallet_disable.py
@@ -23,9 +23,9 @@
         assert_raises_rpc_error(-32601, 'Method not found',
                                 self.nodes[0].getwalletinfo)
         x = self.nodes[0].validateaddress('3J98t1WpEZ73CNmQviecrnyiWrnqRhWNLy')
-        assert(x['isvalid'] == False)
+        assert x['isvalid'] == False
         x = self.nodes[0].validateaddress('mneYUmWYsuk7kySiURxCi3AGxrAqZxLgPZ')
-        assert(x['isvalid'] == True)
+        assert x['isvalid'] == True
 
         # Checking mining to an address without a wallet. Generating to a valid address should succeed
         # but generating to an invalid address will fail.
diff --git a/test/functional/wallet_dump.py b/test/functional/wallet_dump.py
--- a/test/functional/wallet_dump.py
+++ b/test/functional/wallet_dump.py
@@ -34,10 +34,10 @@
                     keypath = None
                     if keytype == "inactivehdseed=1":
                         # ensure the old master is still available
-                        assert(hd_master_addr_old == addr)
+                        assert hd_master_addr_old == addr
                     elif keytype == "hdseed=1":
                         # ensure we have generated a new hd master key
-                        assert(hd_master_addr_old != addr)
+                        assert hd_master_addr_old != addr
                         hd_master_addr_ret = addr
                     elif keytype == "script=1":
                         # scripts don't have keypaths
@@ -142,14 +142,14 @@
 
         # Make sure the address is not IsMine before import
         result = self.nodes[0].getaddressinfo(multisig_addr)
-        assert(result['ismine'] == False)
+        assert result['ismine'] == False
 
         self.nodes[0].importwallet(os.path.abspath(
             tmpdir + "/node0/wallet.unencrypted.dump"))
 
         # Now check IsMine is true
         result = self.nodes[0].getaddressinfo(multisig_addr)
-        assert(result['ismine'] == True)
+        assert result['ismine'] == True
 
 
 if __name__ == '__main__':
diff --git a/test/functional/wallet_keypool.py b/test/functional/wallet_keypool.py
--- a/test/functional/wallet_keypool.py
+++ b/test/functional/wallet_keypool.py
@@ -21,8 +21,8 @@
         wallet_info_old = nodes[0].getwalletinfo()
         assert_equal(wallet_info_old['hdseedid'],
                      wallet_info_old['hdmasterkeyid'])
-        assert(addr_before_encrypting_data[
-               'hdseedid'] == wallet_info_old['hdseedid'])
+        assert addr_before_encrypting_data[
+            'hdseedid'] == wallet_info_old['hdseedid']
 
         # Encrypt wallet and wait to terminate
         nodes[0].node_encrypt_wallet('test')
@@ -33,9 +33,9 @@
         addr_data = nodes[0].getaddressinfo(addr)
         wallet_info = nodes[0].getwalletinfo()
         assert_equal(wallet_info['hdseedid'], wallet_info['hdmasterkeyid'])
-        assert(addr_before_encrypting_data[
-               'hdseedid'] != wallet_info['hdseedid'])
-        assert(addr_data['hdseedid'] == wallet_info['hdseedid'])
+        assert addr_before_encrypting_data[
+            'hdseedid'] != wallet_info['hdseedid']
+        assert addr_data['hdseedid'] == wallet_info['hdseedid']
         assert_raises_rpc_error(
             -12, "Error: Keypool ran out, please call keypoolrefill first", nodes[0].getnewaddress)
 
@@ -66,7 +66,7 @@
         addr.add(nodes[0].getnewaddress())
         addr.add(nodes[0].getnewaddress())
         addr.add(nodes[0].getnewaddress())
-        assert(len(addr) == 6)
+        assert len(addr) == 6
         # the next one should fail
         assert_raises_rpc_error(
             -12, "Error: Keypool ran out, please call keypoolrefill first", nodes[0].getnewaddress)
diff --git a/test/functional/wallet_labels.py b/test/functional/wallet_labels.py
--- a/test/functional/wallet_labels.py
+++ b/test/functional/wallet_labels.py
@@ -116,7 +116,7 @@
             node.setlabel(address, label.name)
             label.add_address(address)
             label.verify(node)
-            assert(address not in node.getaddressesbyaccount(""))
+            assert address not in node.getaddressesbyaccount("")
 
         # Check that addmultisigaddress can assign labels.
         for label in labels:
diff --git a/test/lint/lint-format-strings.py b/test/lint/lint-format-strings.py
--- a/test/lint/lint-format-strings.py
+++ b/test/lint/lint-format-strings.py
@@ -56,8 +56,8 @@
     >>> len(parse_function_calls("foo", "#define FOO foo();"))
     0
     """
-    assert(type(function_name) is str and type(
-        source_code) is str and function_name)
+    assert type(function_name) is str and type(
+        source_code) is str and function_name
     lines = [re.sub("// .*", " ", line).strip()
              for line in source_code.split("\n")
              if not line.strip().startswith("#")]
@@ -71,7 +71,7 @@
     >>> normalize("  /* nothing */   foo\tfoo  /* bar */  foo     ")
     'foo foo foo'
     """
-    assert(type(s) is str)
+    assert type(s) is str
     s = s.replace("\n", " ")
     s = s.replace("\t", " ")
     s = re.sub(r"/\*.*?\*/", " ", s)
@@ -95,7 +95,7 @@
     >>> escape(r'foo \\t foo \\n foo \\\\ foo \\ foo \\"bar\\"')
     'foo [escaped-tab] foo [escaped-newline] foo \\\\\\\\ foo \\\\ foo [escaped-quote]bar[escaped-quote]'
     """
-    assert(type(s) is str)
+    assert type(s) is str
     for raw_value, escaped_value in ESCAPE_MAP.items():
         s = s.replace(raw_value, escaped_value)
     return s
@@ -110,7 +110,7 @@
     >>> unescape("foo [escaped-tab] foo [escaped-newline] foo \\\\\\\\ foo \\\\ foo [escaped-quote]bar[escaped-quote]")
     'foo \\\\t foo \\\\n foo \\\\\\\\ foo \\\\ foo \\\\"bar\\\\"'
     """
-    assert(type(s) is str)
+    assert type(s) is str
     for raw_value, escaped_value in ESCAPE_MAP.items():
         s = s.replace(escaped_value, raw_value)
     return s
@@ -143,11 +143,11 @@
     >>> parse_function_call_and_arguments("foo", 'foo("foo")')
     ['foo(', '"foo"', ')']
     """
-    assert(type(function_name) is str and type(
-        function_call) is str and function_name)
+    assert type(function_name) is str and type(
+        function_call) is str and function_name
     remaining = normalize(escape(function_call))
     expected_function_call = "{}(".format(function_name)
-    assert(remaining.startswith(expected_function_call))
+    assert remaining.startswith(expected_function_call)
     parts = [expected_function_call]
     remaining = remaining[len(expected_function_call):]
     open_parentheses = 1
@@ -196,7 +196,7 @@
     >>> parse_string_content('1 2 3')
     ''
     """
-    assert(type(argument) is str)
+    assert type(argument) is str
     string_content = ""
     in_string = False
     for char in normalize(escape(argument)):
@@ -223,7 +223,7 @@
     >>> count_format_specifiers("foo %d bar %i foo %% foo %*d foo")
     4
     """
-    assert(type(format_string) is str)
+    assert type(format_string) is str
     n = 0
     in_specifier = False
     for i, char in enumerate(format_string):